Week 6: Lecture 1: Classifying And Naming Organisms Flashcards
Taxonomy
The science of naming and classifying organisms within groups. (Taxa)
Phylogeny
The evolutionary history of a species or a group of species (tree of life.)
Systematics
The science of determining evolutionary relationships among organisms.
4 criteria for classifying organisms
- Morphological characters
- Fossil record
- Embryology
- Molecular analysis (genetic differences)
Homologous characters
Come from a common ancestor between species which share a characteristic.
Analogous characters
Different species have similar characters but this isn’t due to a recent ancestor but because their structure have the same function and are successful in a particular environment.
Which characters are the important ones for classification?
Homologous
Two types of characters within homologous characters
Primitive and derived
Can a single character be both primitive and derived?
Yes
Primitive characters also known as…
Ancestral characters
Why can it be difficult to find primitive characters in living organisms?
Because primitive characters of common ancestors aren’t present in the living species today.
Missing link
An ancestor which connects two big groups of living species.
Where can a missing link be found?
The fossil record
Embryos
Embryos may have primitive characters that living species don’t,
Shared characteristics in embryos may mean a common ancestor
How to test for genetic similar by molecular analysis?
Genome sequencing
